Today’s lesson focused on the topic of electricity, specifically reviewing series and parallel circuits. The instructor explained the differences between open and closed circuits, highlighting that current flows in closed circuits but not in open ones. Key concepts discussed included the flow of current from the positive to the negative terminal of a battery and the differences between series circuits, where current remains the same throughout, and parallel circuits, where voltage is constant across components. Students were encouraged to remember important terminology to aid in their understanding of circuit diagrams and configurations.